Harrington Hoists and Cranes (N)ER Hoist - ((N)ER2) User Manual
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7.0 Troubleshooting
HAZARDOUS VOLTAGES ARE PRESENT IN THE HOIST AND IN CONNECTIONS BETWEEN
COMPONENTS.
Before performing ANY maintenance on the equipment, de-energize the supply of electricity to the
equipment, and lock and tag the supply device in the de-energized position. Refer to ANSI Z244.1,
“Personnel Protection – Lockout/Tagout of Energy Sources.”
To avoid a shock hazard, DO NOT perform ANY mechanical or electrical maintenance on the dual speed (or
VFD control) hoist within 5 minutes of de-energizing (disconnecting) the trolley or hoist. This time allows the
internal VFD capacitor to safely discharge.
Only trained and competent personnel should inspect and repair this equipment.
Do Not perform “withstand voltage” test or “insulation resistance” measurement (megger) with the VFD
connnected.
Do Not remove power to the hoist or trolley during operation.
Do Not connect power to the output of the VFD.
When handling VFD provide ESD protection.
Table 7-1 Troubleshooting Guide
Symptom
Cause
Remedy
Hoist moving in
wrong direction
Power supply
reversed phased
Switch 2 of the 3 power supply cord wires at the power source.
(Refer to Section 3.7.11 for instructions on how to check for
correct power supply phase connection.)
Improper electrical
connections
Refer to wiring diagram and check all connections.
Hoist will not operate
Loss of power
Check circuit breakers, switches, fuses, and connections on
power lines/cable.
Wrong voltage or
frequency
Check voltage and frequency of power supply against the rating
on the nameplate of the motor.
Hoist overloaded
Reduce load to within rated capacity of hoist.
Motor overheated
and thermal overload
protector has tripped
See Trouble Shooting Problem "Motor or brake overheating".
Improper, loose, or
broken wire in hoist
electrical system
Shut off power supply, check wiring connections on hoist control
panel and inside push-button pendant.
Brake does not
release
Check motor brake coil for continuity. Replace brake if needed.